Walker was the 16-year-old house guitarist at the Matrix, one of San Francisco's top clubs, and soaked up shows at Bill Graham’s Fillmore West, where it wasn’t unusual to see an evening of music that featured rock, blues, jazz, soul, gospel and African acts side by side.

“At the Matrix, I was a young cat still learning his craft, but guys like Magic Sam and Albert King took a liking to me,” he says. “They could see I was sincere and I would learn from them. At the Fillmore, you took in all this music you might not otherwise have heard. You got educated.”

The education laid the groundwork for one of the more adventurous careers in contemporary blues, punctuated by the recent release of “Hellfire” (Alligator), a wide-ranging stroll through Walker’s genre-hopping tastes, from the Stones-like blues-rock of “Ride All Night” and the gospel-soaked anthem “Soldier for Jesus” to a feisty interpretation of Hank Snow’s country classic “Movin’ On.”

“I got a bit wilder with the guitar than I ever have on (title track) ‘Hellfire’ – it’s a bit over the top,” the dreadlocked guitarist says with a laugh. “I like to get younger people into the blues. If you’re gonna do your grandfather’s blues, you’re not gonna bring younger people into it. If there’s one thread on this album, that’s it.”

Walker was indoctrinated in a similar manner in his San Francisco neighborhood. Sly Stone was more of an inspiration than an actual mentor. By the time Walker started performing, Stone was already a top San Francisco-based producer, working with rock acts such as the Beau Brummels and Grace Slick’s Great Society while putting together his ground-breaking group Sly and the Family Stone.

Bloomfield was a different story. “He was a few years older but he was huge part of my development,” Walker says of his roommate. “Everyone would come to pay homage to Michael. Bob Dylan would come to the house. But it didn’t matter who you were, Michael would open his door to everyone. Through Michael, I got to know Muddy Waters, and I ended up opening shows for Muddy for a couple of weeks.”

But Bloomfield struggled with drug abuse (he eventually died of an overdose in 1981) and Walker found himself on a similar downward spiral in the mid-‘70s. That’s when he pulled the plug on his blues career and dove into gospel.

“I was into gospel as a kid, going to church with my grandmother,” he says. “A good friend of mine asked me to fill in on bass with his gospel group (Oakland’s Spiritual Corinthians) in 1975. I went to rehearsal, they saw I could play guitar and I was hired. I went for one show and stayed for 10 years. I needed that experience, coming out of blues and rock and living with Bloomfield. I got to see the good part of the secular side, and the seedy side. A lot of my friends were dropping like flies and I made a point to change, or I would have been an obituary like everyone else.”

In the mid-‘80s Walker resumed his blues career, taking to heart some advice another mentor, blues great Willie Dixon, once gave him.

“The big impression that Willie made on me when I went to visit him at his house in Glendale (Calif.) is to be myself,” Walker says. “He said, ‘You play a little of that, a little of this, you play all over the place. Make all those places your place.’ It used to be if you played blues you couldn’t play rock, if you played gospel you couldn’t play R&B. He gave me permission to do all that. For me, blues and gospel are the root of it all because they are the most emotionally direct. They’re soul to soul. You don’t need theory, a smoke machine or dancing girls to put them across. Now you need a show, but back then all you needed was a guitar to tell your story.”

Walker’s career took off and he released a series of acclaimed albums, some for major labels, over the next two decades. But in recent years he found himself without a record deal and self-financed “Hellfire” while working with renowned blues producer-drummer Tom Hambridge (who has previously produced Buddy Guy and Susan Tedeschi, among others). He ended up signing to Chicago-based Alligator Records, which released “Hellfire” earlier this year.

Alligator founder Bruce Iglauer “and I are brothers in the same lodge,” Walker says. “He’s the last man standing in blues in many ways. This ain’t no easy business, but Bruce found a way to stay relevant and change with the times.”

That ability to adapt and incorporate new elements into his sound have been hallmarks of Walker’s career, and account for his standing as one of the premier blues guitarists of the last three decades.

“Since the day I started playing, you’re constantly reminded of the tradition and staying within that,” he says. “But the blues has to grow, it has to breathe, and you have to take chances. Everybody I’ve admired has pretty much pushed themselves beyond the expected. B.B. King did ‘The Thrill is Gone’ with strings. ‘Born Under a Bad Sign’ by Albert King is not straight blues; it has Booker T and the MGs on it. It’s more funk than blues. B.B. says music is inclusive. I used to like to eat chicken, but I didn’t like it seven days a week. I’m the same way with music.”

His advice to young blues guitarists who want a career like him?

“Pick up a violin,” he says with a laugh. “There are too many guitar players. You better do it because you love it. When everything goes south, the monitors quit, you can’t find label, all you got is music. If it doesn’t excite you, you won’t excite somebody else. You have to be believable, and the only way to do that is to fulfill that original need you had every time you play.”